Okay, I thought of adding this response as a comment, but since it ended up being so lengthy, I decided to make a separate post. The original comment is here and was caught by the Akismet as spam. I’ve since approved it to be visible.

A response to John Lucidi

First, I’d like to mention that your post was caught in my spam filter (Akismet) due to the number of links you included, so it wasn’t a matter of my not wanting your comment to appear. I just don’t look at posts caught by Akismet very often since it’s almost always pure, unadulterated spam. I have, I believe, read your comment posted on other sites, so one could make an argument that copy/paste behavior by someone who admits an interest in an industry’s success is actually spam. Indeed, I hold that it is.

Nevertheless, I’m willing to approve the comment if only to address the points you’ve made for public record.

The first thing I noticed in your comment was that the Bridgestone link [PDF] was actually to a marketing pamphlet hosted on your own site rather than an actual independent study or measurement as you claim. I contend that Bridgestone has a financial interest in the “nitrogen-filled tire” industry, and note that this pamphlet is not available on their domain. In fact, the only mention of nitrogen in tires I could locate was this quote:

Because race tires are subject to much higher operating temperatures, the air to inflate them is filtered to remove moisture. Moisture inside a race tire could become steam, creating potential problems. Most teams actually replace this filtered air with nitrogen.

My contention that Bridgestone has a financial interest is largely based on the web address included on the marketing pamphlet which is to http://www.trucktires.com and they doubtless have either an affiliation with or provide their own nitrogen filling service for over the road truckers. Big rig trucks have tires that include far more sidewall rubber surface and larger volumes of gas within, and the tires are subjected to wear and use that far exceeds that of the average commuter, so it may actually be that there have been studies done on OTR truck tires that reveal a benefit to having nitrogen-filled tires.

But this doesn’t relate or equate to any benefit to having nitrogen -filled tires on a passenger car. If we concede for a moment (and I’m not actually doing so without seeing an independent study that isn’t a marketing brochure for a company attempting to make a buck) that there is a benefit, which outweighs the exorbitant cost, for OTR truckers to have nitrogen-filled tires, it still must be considered that the tire of a truck has a far greater surface area of sidewall rubber and a larger volume of gas within which may actually create faster rates of diffusion for both gas molecules. There are more molecules and more available avenues of egress.

So, your “proof” isn’t actually proof of anything other than the fact that Bridgestone Firestone has an affiliation or at least some sort of interest in nitrogen-filled tires for OTR trucks. I saw no mention in this marketing pamphlet (your “proof”) that referenced an independent study.

There is, however, an independent study conducted by consumer reports that was conducted on passenger car tires. Their results showed that in one year nitrogen-filled tires lost 2.2 psi while tires filled with normal air mix lost 3.5 psi. This is a difference of 1.3 psi over a full year and certainly nothing close to 4 to 6 times “faster than nitrogen.” I also found it interesting that you’re quick to mention that rate as are many other advocates of this expensive and unnecessary method of filling tires, but never is the rate itself defined. What are the units measured over what period of time? Moreover, the Consumer Reports study also demonstrates that both molecules are diffused over time, with nitrogen diffusing at a slightly slower rate, which is something that I readily conceded to in my initial post.

With regard to tire wear from chemical aging, I’ve again conceded that pure, nitrogen would halt this. From the inside! Surely you realize that oxygen and moisture in the air outside the tire can and will permeate the side wall of a tire. Normal atmospheric pressure, after all, is still a pressure and the molecules of O2 and H2O are variable excited depending upon pressure and temperature and will collide with the same rubber sidewalls from the opposite side. Fortunately, this isn’t a concern since chemical wear, for the average commuter, occurs at a rate that is far slower than physical wear. I have yet to replace a set of tires due to chemical aging -inside or out. I realize I can’t speak for you, but I’m willing to bet $5.00 via Paypal that I can find an independent source that shows the most common reason for tire replacement is worn tread.

You say that “[i]t is a well proven fact within the tire industry that nitrogen inflated tires maintain their pressure better than air filled tires.” I don’t deny this. But there isn’t enough concern with tire pressure loss (both molecules will effuse) that I’m willing to pay for nitrogen. There’s no need for the average consumer to fill their tires with nitrogen since they need only check (or have checked) their tire pressure regularly. I don’t think I’ve ever had an oil change that didn’t include this as a matter of course and I regularly check my own.

There is, of course, the argument you’ve posited that the average consumer doesn’t check their tire pressure and that at least one tire is under-inflated, etc.

But this argument is utter bollocks when examined closely. The under-inflated tire is rarely due to diffusion of air molecules through the side-wall and is nearly always because of some other issue such as a puncture, fissure, poor seal, or faulty valve stem or valve. This is logically the case since if conditions are equal for each tire, an anomaly must have an alternative explanation other than diffusion or gas molecules permeating the sidewalls. This is an important point since each of these issues create points of egress that are large enough for both molecules. At this point, Graham’s Law takes over and the nitrogen will diffuse at a faster rate. This is not a matter of debate, it’s physics. QED.

Additionally, if we were to concede that pressure loss were problematic due to the owner not participating actively in preventive maintenance, then we also have to remember that nitrogen also diffuses and looses pressure. Therefore, what’s needed isn’t to charge $60.00 per tire to replace air with nitrogen but to educate the public on the importance of preventive maintenance checks and services. If the owner just gets their oil changed at a reputable service station, their tires will be checked and pressurized if necessary.

The “average consumer is ignorant” argument is like saying the average person doesn’t floss or brush twice daily so they should visit their dentist once a month for a professional cleaning.